You can easily see why it takes more than an Encyclopaedia to be able to follow what is going on from just this little quote. There are many twists and turns to follow in pursuit of knowledge and its power that has been purpose of many secret agencies since 'his'-story began. Even before records of history that extend (by way of stones and symbols) to beginnings of man's thoughts. These beginnings did not start with language due to some God-given gift and they did not need alphabets or other form and structure such as Locke's 'tabula rasa' would have us believe. Here we see Jewish and Muslim as well as Catholic myth-makers were involved in cryptic or coded information. It is important to remember that Islamic people didn't have as complete a 'Dark Ages' destruction of knowledge despite efforts of Caliph Omar. Hermes Trismegistus is reckoned by many to have been cause celebré or namesake of Hermetics and yet Barrett would have us believe he and his work did not exist until Catholic Churchians had developed Hermeneutics. Talk about 'revisionist history' or Hellenized plagiarization! "Hermes Trismegistus
There is considerable doubt as to when works of Hermes Trismegistus were written, but it is certain that no one person by that name ever existed. The name means Hermes thrice-greatest, Hermes being Greek God of spoken word - 'logos' - identified with Mercury, winged messenger God of Romans, and with Thoth, Egyptian God of writing, itself a magical activity not understood by common man {Emphasis added.}.(Note that Mercury - both astrological planet and liquid metal - was of supreme importance in alchemy.) Thoth was historian, and creator of all-important calendar by which not only history, but movement of Sun, Moon and stars could be measured. {Marshack is a well-respected authority and has proven a 15-30,000+ year old calendar of great precision existed in Iberian region of Portugal.} As scribe of Gods Thoth was custodian of all knowledge. Knowledge is power; knowledge known only to few is even more so. Under intermingling of philosophers and religious scholars of different cultures {Read propagandists or myth-makers}, Thoth/Hermes became God of esoteric knowledge and power. A priest, philosopher or magician whose works were ascribed to Hermes Trismegistus, was human amanuensis of Gods.
Whoever or how many people 'he' was {If Moses, then it would have involved his sister Mariae, who has alchemic treatises intact and credited to her, it might mean 'he' is a 'she'.}, Hermes Trismegistus was author of what became known as Hermetic texts, or 'Corpus Hermeticum', a vast amount of writing on esoteric religion. (The complete 'Corpus Hermeticum' in English translation fills three large volumes.) {We will see more factual reference to thirteen.}
It was thought at one time that Hermes Trismegistus lived at around time of Pythagoras, or perhaps of Moses; references in Hermetic texts to teachings of Jesus {Iesa would have been original name in another language. Jesus of Nazareth was named after this concept of sun [son] and 'Brotherhood of Man'.} were believed to be prophetic foreshadowings of these great truths. {If Jesus studied to find discipline and truth 'within' 'the living father' so should everyone. Thus idea of an easy and accessible, by 'special dispensations’ and confessions type of 'Salvation' would not have such credibility or market acceptance. Pardon my coarse use of business terms to apply to effort of these 'religious scholars' who like to be thought of as having 'Divine Inspiration'.} Later scholarship, however, has shown that 'Corpus Hermeticum' was written sometime in first five centuries AD, largely in Egypt, as a fusion of Greek and Egyptian esoteric teachings.
{But Michael Grant, in his well-respected 'The Rise of Greeks' makes note that cult of Thoth/Hermes and its equivalent 'Imhotep/Asklepios' was main intellectual belief during time of Pythagoras. Others know Pythagoras as a Therapeutae ['Dead Sea Scrolls Deception' by Baigent and Leigh, as well as Rabbis galore.] which is origin of Essenes that Gardner tells us are an outgrowth of 'The Great White (not racial) Brotherhood of Master Craftsmen'. The real answer is far more ancient, as we shall see, but for now it is important for you to know these things at a minimum, in order to judge what is being said.}
The Hermetic texts were known to Islamic scholars in medieval times, but it did not come to attention of West until they were translated into Latin in 1471 {There are others who even dispute this date. How did Albertus, Aquinas and Bacon get their knowledge? etc.} by Italian Marsilio Ficino. The texts included works on religion, philosophy, magic, medicine, alchemy and astrology, all of which were closely linked. They include among many others 'Emerald Tablet', or 'Tabula Smaragdina', which begins with saying usually shortened to 'As Above, so below', {There is a great book of recent date by this name in New Age bookstores. Barrett uses Dictum of Hermes Trismegistus on his back cover flap as it is taken from Macoy's 'General History, Cyclopedia and Dictionary of Freemasonry', 1850.} and which discusses Philosopher's Stone; 'Poimandres', 'The Good Shepherd', a Gnostic text about infinite light of God, and man's journey to enlightenment, and 'Perfect Sermon of Asclepius {A variant of Asklepios which was mentioned before.} which speaks of divine Unity above a hierarchy of spiritual beings, and of man, who possesses both body an spirit, having a divine nature." (2)
Thus you see 'living father within' that Jesus taught about; and even Barrett admits 'Source' of teaching of Jesus is Grail which has a lot to do with Dag (or Nag) Hammadi 'finds’. These were deciphered from Coptic in 1971 and I highly recommend 'The Gospel of Thomas'. So 'churchians' in hot pursuit of this knowledge Gnostics hid in protective urns when they were defending Alexandria's Library through four attacks, also wanted to keep people 'ignorant'. Jesus did not! The Cathars were later genocidally dealt with in a Crusade. This IS serious business, and it was not long ago that anyone speaking such things would be victim of 'Blasphemy Laws' (ended in 1951 in England) or worse. I can attest to major problems in my own life despite our apparent freedoms; but this is not forum for such digressions.
It is important to deal with his assertion that Islamic scholars 'in medieval times' knew hermetics or alchemy. He seems to suggest in a back-handed way that there was no earlier date for these things even in relatively free Islamic world. This is a lot like 'flat earth' and a host of other fictions that seek to minimize knowledge before obvious Empire-builders had destroyed egalitarian (Gaian or matriarchal in some cases) truth, of even better times. Better than any yet achieved, not just better than Greeks who made an art of slavery and Romans who Greeks correctly called 'barbarians'.